Following the campaign in France Germany captured a large number of 75mm 1897 field guns, after experience in Russia demonstrating the short comings of the new Pak 38 a more powerful weapon was required. As in stopgap measure until the Pak40 was ready for service the barrels from the captured 75mm field guns were removed and attached to Pak 38 carriages.

These weapons were never highly regarded due to the low muzzle velocity making accurate shooting, particularly against moving targets difficult and there was also a high rate of failure. These weapons were replaced when the Pak 40 entered service.

Both Krupp and Rheinmetall-Borsig had been asked to develop 88mm anti-aircraft guns that were capable of firing in a ground role, the Rheinmetall-Borsig gun was completed first and designated the Flak 41. Due the Flak 41 displaying some issues it was decided to keep the Krupp gun in development, the aim being to develop a weapon that could be used in both tank and anti-tank mountings. The result was the Pak 43.

The Pak 43 entered production in 1943 and was an extremely powerful weapon, capable of dealing with any tank it would face. It was however a massive weapon, well beyond the reasonable weight for an anti-tank weapon. The weight coupled with the immense size - the gun alone being over 6 meters long, this meant that it was extremely difficult to handle on the field.

The Pak 43 is often stated to be the best anti-tank weapon of the war, in terms of raw firepower it is probably right, however its size and weight limited its combat efficiency.

Pak 43 Statistics

Total Length

920cm

Length of Gun

635cm

Calibre

8.8cm

Elevation

-8°, +40°

Transverse

360°

Rate of fire

6-10

Rifling

32 grooves

Weight in Action

3600kg

Performance of the Pak 43 Anti-Tank Gun

Ammunition

Weight of shot/shell

Complete Weight

Bursting Charge

Propellant Charge

Muzzle Velocity

Angle

Plate

100m

500 m

1000m

1500m

2000m

Pzgr Patr 39-1

10kg

23kg

-

6.83kg

1000m/s

30

MQ

203

185

165

148

132

Pzgr Patr 39/43

10.16kg

23.35kg

-

6.83kg

1000m/s

30

MQ

203

185

165

148

132

Pzgr 40

7.3kg

-

-

-

1130m/s

30

MQ

237

217

193

171

153

Spgr Patr L/4.7

9.4kg

19.3kg

-

3.4kg

750m/s

-

-

-

-

-

-

-

Spgr Patr 43

9.4kg

19.3kg

-

3.4kg

750m/s

-

-

-

-

-

-

-

Production of Pak 43 Anti-Tank Guns and Ammunition by year (Ammunition in thousands)

Designed by Krupp the 7.5cm Pak 41 operated on the same Gerlich principle as the 2.8cm Pzb. With this weapon the projectile was squeezed from 75mm to 55mm, this enabled the projectile to be fired at a high velocity of over 1,100m/s. The very high muzzle velocity (well over 1,000fps higher than the Pak40) gave the weapon immense power, capable of penetrating very thick armour.

The tungsten cored projectiles fired by the Pak 41 were an enlarged version of those used on the 2.8cm Pzb. Unlike other weapons the gun shield was used as the structure rather than just being an addition, this reduced the weight.

The Pak 41 entered production in 1942 but due to the ban on tungsten in ammunition only 150 were ever completed. Once supplies of ammunition were depleted some had Pak40 barrels fitted.

Before the advent of the Second World War the Wehrmacht had issued contracts Krupp and Rheinmetall-Borsig to develop a 75mm anti-tank gun. Development of the weapon was slow as it was initially felt there was little need for a heavy, slow anti-tank gun. Experience in Russia however had shown that the current anti-tank weapons, namely the Pak 36 and Pak 38 did not have sufficient power to deal with the latest Russian tanks and so a more powerful weapon was required.

The 75mm project was therefore given higher priority and the result was the Pak 40. Production of the Pak 40 began at the beginning of 1942 and the first weapons were issued in the spring. Production of the Pak 40 was initially slow with only 1,360 being completed in 1942 but by 1943 and 1944 the numbers being built increased massively with over 7,000 in 1943 and just under 11,000 in 1944. This substantial increase in weapons being produced in 1944 did not however mean a large increase in the number of weapons in the hands of the army however, due to the massive losses in equipment experienced in 1944. For example, between January 1st and September 30th 1944 7,954 Pak40s were produced of which 7,060 were assigned, in the same period 6,640 guns were lost - in the final three months of the year a further 2,000 were lost.

The Pak 40 was essentially an enlarged version of the Pak 38, this lead to an increase in firepower but the mobility seen in earlier German anti-tank weapons was lost, the losses posted above are a testament to the difficultly of moving the pak40, particularly in retreat. The Pak40 did however add much needed firepower to the German army and was capable of dealing with the majority of targets it faced.

As with previous anti-tank guns armour piercing composite rigid ammunition was produced but due to tungsten supplies only around 50k of these were completed.

Pak 40 Anti-Tank Gun Statistics

Total Length

cm

Length of Gun

370.2 cm

Calibre

7.5cm

Elevation

-6°, +22°

Transverse

65°

Rate of fire

12-15

Rifling

32grooves

Telescope magnification

3x

Weight in Action

1425kg

Performance of the Pak 40 Anti-Tank Gun Ammunition

Ammunition

Weight of shot/shell

Complete Weight

Bursting Charge

Propellant Charge

Muzzle Velocity

Angle

Plate

100m

500 m

1000m

1500m

2000m

Sprgr Patr 34

5.8kg

9.15kg

640gm

780gm

-

-

-

-

-

-

-

-

Pzgr 39

6.8kg

12kg

16gm

2.75kg

792m/s

30

MQ

106

96

85

74

64

Pzgr 40

3.2kg

9.55kg

-

3.8kg

990m/s

30

MQ

143

120

97

77

-

Sprgr 38 H1/B

4.65kg

8kg

kg

900gm

450m/s

30

MQ

70

70

-

-

-

Production of Pak 40 Anti-Tank Guns and Ammunition by year (Ammunition in thousands)

The advancement of tank armour in the late 1930's had rendered the Pak 36 obsolete and a more powerful weapon was sought. The result was the 50mm Pak38 anti-tank gun, the Pak38 was of the same design as the Pak36 but featured a muzzle break to decrease recoil stress on the mount and a double shield each 4mm thick. As with its predecessor the Pak 38 was designed to be as light as possible, the weapon was however double the weight of the Pak 38 but still nearly 200kg lighter than the British 6 Pounder.

Production of the Pak38 around the beginning of 1940 and issued to units towards the end of the year. By the invasion of Russia in June 1941 just over 1,000 were in the hands of the Wehrmacht.

The Pak 38 was a significantly more powerful weapon than the Pak36, however this increase in power was still not enough to defeat the British infantry tanks such as the Matilda Mk II or the well armoured Russian tanks such as the T-34 at medium to long ranges. The Pak38 became the backbone of the German anti-tank force for the mid part of the Second World War until it was replaced by heavier, more powerful weapons such as the Pak40.

As with the Pak36, special tungsten cored armour piercing composite rigid ammunition was provided which significantly improved the penetrative power of the weapon at close/medium ranges. This type of ammunition was produced in large numbers making up approximately 36% of armour piercing ammunition in 1941 and 1942, by 1943 however stocks of tungsten had been greatly reduced and so it could no longer be used for ammunition. The tungsten in existing ammunition may also have been retrieved for more vital use such as machine tools.

The Panzerabwehrkanone 36 (Pak) was the standard anti-tank weapon of the Wehrmacht for the early part of the second world war. The Pak 36 was designed to be extremely mobile and easily pulled by horses or manpower. The combat ready weight of the Pak 36 was only just over 430kg (946lb), half that of the British 2 Pounder gun, this enabled the Pak 36 to be much more manoeuvrable and easily manhandled in difficult terrain.

The Pak36 however was a very underpowered weapon, performance was vastly inferior to that of the British 2 Pounder and only equalled that of the French 25mm anti-tank gun. For the invasion of Poland the pak36's performance was adequate but against the French tanks of May 1940 the poor performance was clearly highlighted. The heavy tanks such as the French Char B1 and the British Matilda were virtually immune to the Pak36, even the lighter tanks such as the H39 and R35 proved difficult targets for the Pak 36.

To attempt to improve the performance of the Pak 36 tungsten cored ammunition, Pzgr 40 was produced, this was a lighter projectile than the standard armour piercing ammunition and thusly had a significantly higher muzzle velocity, this significantly improved performance. As the projectile was light it lost energy rapidly and the performance increase only lasted for a few hundred metres before it fell below that of standard ammunition. Production of this ammunition appears to have begun around June 1940, there is some debate as to whether or not it was issued during the Battle of France, if it was the numbers would have been extremely small. Later attempts to keep the weapon useful as tank armour increased involved a spigot bomb and although it could defeat significant amounts of armour its range was limited to around 300m

The pak 36 had seen extensive production before the beginning of WWII and by October 1939 over 10,000 had been issued and by May 1940 this number had risen to around 14,000. With the introduction of the Pak38 and tank armour advances rendering the Pak 36 obsolete production was scaled back in 1941 and the final weapons were completed in 1942.

The 2.8cm s Pzb 41 was one of the more unusual weapons the Second World War, it operated under the Gerlich principle where a tapering bore squeezed a projectile to enable a much higher muzzle velocity. With this weapon a 28mm projectile was squeezed to 20mm achieving a muzzle velocity of around 1,400 m/s.

Compared to a standard weapon of similar calibre the Pzb 41 was significantly more powerful, the weapon was also very light particularly as no elevation/transverse gear was fitted. A double shield consisting of two 4mm thick plates was fitted to give protection against small arms. Introduced in 1941 the Pzb 41 saw limited production,.

The Pzb 41 fired special ammunition that consisted of a tungsten carbide core surrounded by a soft iron body, the body had finds that could be squeezed as the projectile progressed down the tapering barrel. The projectile was also fitted with a magnesium cap. As stated before a very high muzzle velocity was achieved, this significantly improved the performance of the weapon but as the projectile was very light it lost velocity rapidly thus performance at longer ranges was poor.

Testing carried out by the British on a captured Pzb 41 in 1941 showed that while the the entrance hole was small quite a few high velocity fragments emerge from the rear of the place, it was also shown however that the projectile was likely to break up even when hitting a thin plate and could be easily defeated by a spaced armour. A high explosive round was also provided but it is unlikely that it was particularly effective.

In January 1941 a more powerful anti-aircraft gun was requested by the War Office and the 5.25 Naval gun was chosen, the first guns were completed in 1943. There were two separate mountings for the gun, the Mk IA solely for anti-aircraft use and the Mk IB for a dual anti-aircraft/Coastal defence, these had an armoured turret. The guns were first installed in the London area and naval bases such as Plymouth and Portsmouth.

The 4.5" anti-aircraft gun was an adoption of the 4.5" Naval gun, the naval gun was chosen as there was there was no prospect of the 4.7" being developed and put into production soon and as these guns were planned to be placed near naval bases ammunition supplies would be assured and so in 1938 the 4.5" anti-aircraft gun was approved for land service. Some guns were fitted with a mild steel shield and some guns were placed at the coast to be used in a dual anti-aircraft / coastal defence role. By 1944 the guns were being replaced by the 5.25" gun but the weapons were not declared obsolete until 1951.

In the late thirties the British Army were looking for a weapon between the 3" and 4.7" calibre Anti-Aircraft guns. After research it was found that a 3.7" gun firing a 25lb shell could fill the gap and so in 1933 a specification for a 3.7" gun weighing 8 tons, capable of being put into action in 15 minutes and being towed at 25mph was issued. A design by Vickers was accepted and the pilot model passed proof in April 1936 with production being authorised a year later. The first production guns were delivered in January 1938.

The gun was extremely advanced and complicated and was regarded as one of the best weapons of it's type in the world. Production was initially slow, particularly due to it's complicated carriage but modifications to the design to simply it for production helped and peak production was reached for guns in March 1942 (228) and for mountings June 1942 (195).

In January 1941 the War Office issued specifications for a gun that could reach 50,000 feet within 30 seconds and have the ability to fire 3 rounds and have the fourth loaded within 20 seconds. The 5.25" was chosen but for a shorter term solution it was decided to line down the 4.5" gun down to 3.7". A new system of rifling was required, this was known as Research Department (RD) rifling and was first used on the Mk 6 version of the gun introduced in 1943, were a 65 calibre 3.7" liner was inserted in the jacket of a 4.5" gun. By 1942-43 the threat of German aircraft had been greatly reduced and so production decreased.

Many sources state that the 3.7" anti-aircraft gun either couldn't or wasn't used in an Anti-Tank role, this is false. Up until 1938 it had been standard practice for anti-aircraft crews to be trained in a direct fire role, this was dropped due to reduce costs and quicken training. There are multiple reports of the weapons being used against tanks and other direct fire roles, I have also come across the 1944 handbook for direct fire with 3.7" anti-aircraft guns. There was both a SAP and an AP rounds produced during the war for the 3.7" guns and as around 1/3 of a million of these rounds were made it seems very unlikely that the guns were incapable of firing them.

There is no doubt that the 3.7" anti-aircraft gun was not used in an Anti-Tank role to the same degree as the German Flak36, there are many reasons for this - chiefly the weight of the gun and the wish to use the guns in their intended anti-aircraft role aslo that the 25 Pounder was perfectly capable of dealing with the majority of German tanks. Penetration wise the 3.7" anti-aircraft gun was superior to the German Flak36 and with an auto reloader it was a weapon a tank would not like to come across, but at over 20,000lb in weight the Flak36 was clearly easier to handle in the field.

3.7" Gun Data

Mk I-III

Mk VI

Weight of gun and breech

3,931lb

6,552lb

Total length

195.15"

252"

Length of bore

50 cal

65 cal

Rifling

28 grooves, 1/30

28, 1/27

Elevation

-5, +80 degrees

0, +80 degrees

Traverse

360 degrees

360 degrees

Weight in Action (Mobile)

20,514lb

-

Weight in Action (Static)

23,100lb

38,360lb

Rate of fire (Hand)

10

8

Rate of fire (Auto)

25

19

Muzzle Velocity

2600fps

3,425fps

Max horizontal range

20,600 yards

25,600 yards

Max Ceiling

41,000 feet

59,300 feet

Production of 3.7" Anti-Aircraft Guns by year *no data for guns from June onwards, Commonwealth data from May onwards